The majority of research on childhood conduct problems has been conducted on male research participants. Recent data suggest that female conduct problems are increasing and faster than our knowledge of potential gender differences in the development and expression of antisocial behavior. Available research suggests that female childhood conduct problems are under-represented in clinics and potentially expressed in non- traditional behavior difficulties (e.g., relational aggression). Gender differences in the prevalence of childhood conduct problems (i.e., male > female) decrease markedly when assessing for conduct problems outside of the current diagnostic nomenclature. However, further research is needed to determine if behavior such as female relational aggression is a gender normative manifestation of emergent conduct problems grounded in similar biopsychocial correlates as male ODD/CD symptoms. This has clear implications for the classification, assessment, early detection, and treatment of female antisocial behavior. The proposed study uniquely integrates the emotional regulation, relational aggression, and child psychopathy literatures in proposing that emergent female relational aggression is very similar to male ODD/CD symptoms in its association to emotional over-reactivity and other traditional cognitive (e.g., verbal intelligence weaknesses), emotional (e.g., heightened anxiety), and familial (e.g., parenting dysfunction) impairments associated with youth antisocial behavior. In contrast, it is proposed that gender non-normative emergent conduct problems (i.e., male relational aggression and female ODD/CD symptoms) are a marker for a more severe behavioral disturbance characterized by emotional under-reactivity, callous-unemotional traits, and other correlates of the child psychopathy construct (e.g., low anxiety and motivational disinhibition). To test these predictions, a purposive sampling procedure will be used to recruit 160 elementary age children (80 boys and 80 girls in grades 2-5 ) exhibiting varying levels of CU traits from a larger screening sample composed of 4,000+ children enrolled in numerous elementary schools across two local school districts. Recruited participants will complete a two-part multi-method/multi-informant research protocol consisting of various measures of conduct problems (i.e., ODD/CD and relational aggression) and associated indices of emotional (e.g., anxiety), behavioral (e.g., ADHD symptoms), cognitive (e.g., verbal IQ), and familial (e.g., parenting dysfunction) functioning. This includes four performance-based computer measures assessing for emotional reactivity and impulse control processing impairments (i.e., executive and motivational disinhibition) suspected to exhibit different relations to gender normative and non-normative conduct problems. [unreadable] [unreadable]